Browsing by Author "Castañeda Magliona, Fernando"
Now showing items 1-16 of 16
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3-(Triphenylphosphoranylidene)-pentane-2,4-dione and diethyl 2-(triphenylphosphoranylidene)-malonate (BLACKWELL PUBLISHING, 2005-08)The title ylides, 3-(triphenylphosphoranylidene) pentane-2,4-dione, C23H21O2P, (I), and diethyl 2-(triphenylphosphoranylidene)malonate, C25H25O4P, (II), differ in the conformations adopted by their extended ylide moieties. ...
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(TAYLOR & FRANCIS LTD, 2003-11)The diacyl ylide, 3-triphenylphosphoranylidene-2,4-pentanedione (2) can adopt conformations stabilized by ylidic resonance with both acyl oxygens syn- or with one oxygen syn- and the other anti- to cationoid phosphorus, ...
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(TAYLOR & FRANCIS LTD, 2007-01)The diacyl ylid, 3-triphenylphosphoranylidene-2,4-pentanedione 2 can adopt conformations with one oxygen syn- and the other anti- to phosphorus 2a as in the crystal, or with both oxygens syn- to phosphorus 2b. In solution, ...
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(2013)In ylidic triphenylphosphonium carboxylic esters the ester oxygen can be oriented towards (syn) or away (anti) from phosphorus, but except for small ylidic ester groups, e.g., Me, the anti conformer is dominant. With ...
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(SOCIEDAD CHILENA DE QUIMICA, 1998-12)The crystal structure of C42H37O3P2Br has been determined by single crystal X-ray diffraction. The title compound is monoclinic, space group P2(1)/n (Nr. 14), with unit cell parameters a = 11.220(6), b = 14.345(10), c = ...
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(TAYLOR & FRANCIS LTD, 2007)The mixed stabilized triphenyl phosphonium ylides Ph3P= C(CN)CO-R and Ph3P= C(CN)COOR, R= CH3, C2H5, CH(CH3)(2), 1a, c and 2a, b, respectively, have sharp H-1 and C-13 NMR signals, except for 2b in some conditions. Ab ...
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(BLACKWELL PUBLISHING, 2007-01)Crystalline cyano-stabilized triphenylphosphonium ylids with keto or ester groups give rise to an extended electronic delocalization. In methyl 2-cyano-2-(trimethylphosphonio)-ethenoate, Ph3P=C(CN)CO2CH3 or C22H18NO2P, ...
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(Universidad de ChilePrograma Cybertesis, 2006)El oxígeno molecular singulete es la especie excitada de menor energía del oxígeno y se encuentra presente en los sistemas biológicos junto a otras especies reactivas del oxígeno. La alteración del balance normal de las ...
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(Sociedad Chilena de Química, 1980)
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(Universidad de Chile, 2006)Se estudia la descomposición térmica de sales de ésteres de alquiltrifenilfosfonio, Ph3P+-CH2-CO2RX- donde R es -CH3, -CH2-CH3, -CH(CH3)2 o -C(CH3)3 y X- corresponde a Br-, Cl- o TsO-. La formación de especies intermediarias ...
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(BLACKWELL PUBLISHING, 2008-07)The conformations of organic compounds determined in the solid state are important because they can be compared with those in solution and/or from theoretical calculations. In this work, the crystal and molecular structures ...
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(Elsevier, 2009)For stabilized triphenylphosphonium keto ester ylides acyl stretching frequencies of the anti ester group from HF/6-31G(d) calculations fit experimental values with Scale Factor, SF = 0.866, as estimated earlier for the ...
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(MUNKSGAARD INT PUBL LTD, 2001-02)The crystal structures of four alkyl 3-oxo-2-(triphenylphosphoranylidene)butyrates, where the alkyl group is methyl (C23H21O3P .0.5C(6)H(6)), (II), ethyl (C24H23O3P), (III), isopropyl (C25H25O3P), (IV), or tert-butyl ...
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(TAYLOR & FRANCIS LTD, 2003-09)The stabilized phosphorus ylides, Ph3P=C(CO.R')CO.OR, 1, R=Et, R' =CH2P+Ph3; 2, R=R'=Me; 3, R=Et, R'=Me; 4, R=Pr-i; R'=Me, 5, R=Bu-t; R'=Me, adopt a near planar conformation in the crystal which allows extensive electronic ...
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(Sociedad Chilena de Química, 1980)El estudio químico y espectroscópico de los acil etoxicarbonil metilidentrifenilofosforanos I, revela que son compuestos extraordinariamente estables (1). En este trabajo se informa la síntesis de una serie de ílidos ...
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(TAYLOR & FRANCIS LTD, 2008-05)In thermolyses of molten triphenylphosphonium alkyl ester bromides and chlorides, alkyl=methyl, ethyl, isopropyl, at 130 and 225 degrees C, initial attack of the halide ion on the methyl group gives the methyl halide and ...
